Add server-side core-js ES6 polyfill
Add server-side core-js ES6 polyfill

Closes bakape#250
Closes bakape#249

reiclone/doushio,KoinoAoi/meguca,theGaggle/sleepingpizza,theGaggle/sleepingpizza,theGaggle/sleepingpizza,theGaggle/sleepingpizza,reiclone/doushio,KoinoAoi/meguca,theGaggle/sleepingpizza,reiclone/doushio,reiclone/doushio,KoinoAoi/meguca,KoinoAoi/meguca,KoinoAoi/meguca,reiclone/doushio,theGaggle/sleepingpizza